Under the rear of the truck is a GM 14-bolt axle that was sourced from a ’70s motorhome. It has 5.38 Sierra Gear &amp; Axle gears, an ARB Air Locker, Sierra Gear &amp; Axle 4340 chromoly axleshafts, and GM 3/4-ton pickup-application brakes. The four-link, coilover, limiting strap-equipped rear suspension is a near duplicate of the front suspension with the exception of a track bar made from larger diameter 1.75-inch tubing.